Apparatus and method for processing a lithographic printing plate

Abstract

An apparatus and method for processing a lithographic printing plate include a plate transport for conveying the plate through the apparatus, a plate detector for locating the plate in the apparatus and for determining a plate width, one or more nozzles for depositing developer on the plate, wherein the one or more nozzles are arranged to shuttle over the plate or are arranged as a fixed array that spans at least the width of the plate. The plate detector is coupled to the one or more nozzles to selectively actuate the one or more nozzles that are positioned to deposit developer across the plate area, which results in a significant reduction of developer consumption. In preferred embodiments, the nozzles apply developer in accordance with the image on the plate, which enables an even lower consumption of developer.

1 - 10 . (canceled) 
     
     
         11 . An apparatus for processing a lithographic printing plate including a latent image including printing areas and non-printing areas, the apparatus comprising:
 a plate transport configured to convey the plate through the apparatus along a path, the plate including edges defining a plate area and a plate width, and the plate width is defined as an edge-to-edge distance of the plate along a direction perpendicular to the path;   a plate detector configured to locate the plate in the apparatus and to determine the plate width;   one or more nozzles configured to deposit developer on the plate, the one or more nozzles arranged to shuttle over the plate or arranged as a fixed array that spans at least the plate width; and   a controller coupled to the plate detector and the one or more nozzles and configured or programmed to selectively actuate the one or more nozzles that are positioned to deposit the developer across the plate area based on results from the plate detector.   
     
     
         12 . The apparatus according to  claim 11 , wherein the plate detector includes a pushing device to push one of the plate edges against a guide bar, the plate detector further including a detector configured to detect the one of the plate edges of the plate opposite to the guide bar. 
     
     
         13 . The apparatus according to  claim 11 , further comprising an input configured to provide the plate area and/or the plate width from a plate setter or from a prepress workflow system to the controller. 
     
     
         14 . The apparatus according to  claim 11 , further comprising an input configured to provide dot coverage data of an image of the plate from a platesetter or from a pre-press workflow system to the controller. 
     
     
         15 . The apparatus according to  claim 14 , wherein the controller is configured or programmed to adjust an amount of the developer that is deposited by each of the one or more nozzles on a section of the image in accordance with an average of the dot coverage of the section of the image. 
     
     
         16 . The apparatus according to  claim 15 , further comprising one or more second nozzles to selectively deposit a gum solution on the plate. 
     
     
         17 . The apparatus according to  claim 16 , wherein the one or more nozzles and/or the one or more second nozzles include needles. 
     
     
         18 . A method for developing a lithographic printing plate including a latent image including printing areas and non-printing areas, the method comprising the steps of:
 feeding the plate to an apparatus as defined in  claim 11 ; and   developing the image by selectively actuating the one or more nozzles to deposit the developer across the plate area.   
     
     
         19 . The method according to  claim 18 , further comprising the step of:
 gumming the plate by selectively actuating one or more second nozzles to deposit a gum solution across the plate area.   
     
     
         20 . The method according to  claim 19 , wherein an amount of developer and/or an amount of gum deposited on a section of the image is adjusted in accordance with an average dot coverage of the section of the image.